Mode of communication of cholera by John Snow, MD: second edition – London, 1855, pp 162
None of our readers can be ignorant of the opinions of Dr. Snow on the communication of cholera by means of drinking water, nor of the perseverance and energy with which he has sought for facts to corroborate this view. The present work is a recapitulation of all the evidence he has hitherto published, with the addition of certain facts lately acquired. We have read this work carefully, and shall endeavour, in the following critique upon it, to do full justice to Dr. Snow, while we shall strictly examine, as it is our duty to do, if there is anything hollow or unsound in the facts brought forward, or in the arguments founded upon them. Dr. Snow believes not only that cholera is propagated by means of water, but that it is solely and exclusively so propagated. He is therefore obliged, at the very outset of his inquiry, to assume that cholera only spreads where human intercourse is possible. Thus he writes, ‘‘It travels along the great tracks of human intercourse, never going faster than people travel, and generally much more slowly. In extending to a fresh island or continent, it always appears first at a sea-port. It never attacks the crews of ships going from a country free from cholera, to one where the disease is prevailing, till they have entered a port, or had intercourse with the shore. Its exact progress from town to town cannot always be traced; but it has never appeared except where there has been ample opportunity for it to be conveyed by human intercourse.’’ (p. 2)
Citation: Parkes EA. Mode of communication of cholera by John Snow, MD: second edition – London, 1855, pp 162. International journal of epidemiology 2013;42:1543-52.